(just) out of interest/as a matter of interestspokenINTERESTED used to say that you are asking a question only because you are interested and not because you need to know (只是)出于好奇〔提问时用〕 Just out of interest, how much did they offer you? 我只是好奇地问一下,他们打算给你多少钱?
→ (just) out of interest/as a matter of interest at interest1(3)